Haven't tried yet - I don't know if it will play at the standard PAL speed, and not sure if I can control where it starts playing either, from my experiments the other weekend. But from the manuals it looks like I can run test mode over the serial interface on the V2800, so that might offer a bit more control.
(I also need to clean/replace the grip clamp on my 503-clone before I can say if the HF9G would even try to play a PAL disk in test mode...)
TL;DR I'm doing it as an experiment/lark and not promising anything out of it ;)